Magnetic alloy.



ROBERT A. HADFIELD, SHEFFIELD, ENGLAND. MAGNETIC ALLOY Specification of Letters Patent.

Patented Nov. 27, 1906.

Application filed July 5, 1906. Serial No. 324,892.

To all whom it may concern.-

Be it known that I, ROBERT ABBOTT HAD- FIELD, a subject of the King of Great Britain, residing at Shefiield, En land, have invented a certain new and use 1 Improvement in Magnetic Alloys, of which the following is a specification.

The invention is an alloy having magnetic and electric properties especially adapting it for use in ballast-coils, transformer-plates, and like electrical apparatus wherein it is of great importance to reduce the total magnetic and electric losses to the lowest possible degree, and also having improved physical properties in point of capacity for being wor ed, forged, or rolled.

In United States Letters Patent N 0. 745,829, granted to me December 1, 1903, I have set forth an alloy of iron and silicon which is subjected to a described heat treatment and which possesses a magnetic permeability and electric resistance above and a h steresis quality below, respectively, those of the best Swedishcharcoal-iron or, enerall the purest iron commercially o tainab e. I have now discovered that the said i alloy may be rendered more perfectly and readily wrou ht or rolled and also more easily produced in rnaces by the addition of manganese in amount not suflicient to impair the aforesaid im roved magnetic qualities. To make said allby, I melt in any suitable vessel iron, silicon from one to five per cent., and

manganese in a proportion less than one-half of one per cent. of the entire mass, which proportion is not sufficient to disturb the magnetic qualities of the mixture. then cast into ingots and afterward wor ed in the usual way. It is preferable to keep whatever sulfur may exist in the mixture in the lowest proportion possible.

I claim An iron silicon manganese alloy containing silicon from one to five per cent. and manganese in proportion less than one-half of one per cent.

In testimony whereof I have signed my name hereto in the presence of two witnesses.

' ROBERT A. HADFIELD.

Witnesses:

HENRY E. DIXON, FRANK HUTSON.

The allo is 

